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Joel Ullom (Fed)

Dr. Joel Ullom leads the NIST Quantum Sensors Division. He is also a Lecturer in the Department of Physics at the University of Colorado Boulder. Dr. Ullom has worked in the fields of low temperature sensors, quantum electronics, and cryogenic systems since 1994. During this time, he has done research to understand and improve the performance of superconducting transition-edge sensors. He has also worked to develop different types of refrigerators including microcoolers based on quantum tunneling and macrocoolers that reduce the need for liquid cryogens. Dr. Ullom has developed and disseminated a variety of instruments based on multiplexed arrays of cryogenic sensors.

Research Interests

  • cryogenic sensors
  • multiplexed readout techniques
  • advanced cryogenics
  • radiation detection
  • applications of cryogenic sensors in materials analysis, astrophysics, cosmology, fundamental parameters, and quantum information science

Awards

Publications

Most stringent bound on electron neutrino mass obtained with a scalable low temperature microcalorimeter array

Author(s)
Bradley Alpert, Daniel Becker, Douglas Bennett, Joseph Fowler, Johnathon Gard, John Mates, Carl Reintsema, Daniel Schmidt, Daniel Swetz, Joel Ullom, Leila Vale, M. Balata, S. Nisii, A. Bevilacqua, M. De Gerone, G. Gallucci, L. Parodi, F. Siccardi, A. Borghesi, P. Campana, R. Carobene, M. Faverzani, A. Giachero, M. Gobbo, D. Labrbca, R. Morette, A. Nuciotti, L. Origo, S. Ragazzi, G. Ceruti, E. Ferri, G. Pessina, E. Celasco, F. Gatti, R. Dressler, E. Maugeri, D. Schumann, U Koster, M. Lusignoli, P. Manfrinetti, F Ahrens, E Bogini, M. Borghesi, P. Campana, R. Carbene, L. Ferrari Barusso, E. Ferri, G. Gallucci
The determination of the absolute neutrino mass scale remains a fundamental open question in particle physics, with profound implications for both the standard

Speciation of cesium in a radiocesium-bearing microparticle emitted from Unit 1 during the Fukushima nuclear accident by XANES spectroscopy using transition edge sensor

Author(s)
Yoshio Takahashi, Shinya Yamada, Hikaru Miura, Yuichi Kurihara, Oki Sekizawa, Kiyofumi Nitta, Tadashi Hashimoto, Masato Tanaka, Minako Kurisu, Shinji Okada, Takaaki Itai, Hiroki Suga, Teruhiko Kashiwabara, Kohei Sakata, Hideyuki Tatsuno, Ryota Hayakawa, Hirotaka Suda, Takaya Ohashi, Yoshitaka Ishisaki, Takuma Okumura, Yuto Ichinohe, Tasuku Hayashi, Yuki Imai, Hirofumi Noda, Toru Tamagawa, Tadaaki Isobe, Toshiyuki Azuma, William Doriese, Joel Ullom, Daniel Swetz, Malcolm Durkin, Galen O'Neil, Satoshi Kohjiro, Shogo Higaki, Daisuke Tsumune, Masayoshi Yamamoto, Tomoya Uruga
The chemical state of radiocesium (RCs) was determined using X-ray absorption near-edge structure (XANES) in fluorescence mode and microbeam X-ray fluorescence

Patents (2018-Present)

Compact Low-power Cryo-Cooling Systems For Superconducting Elements

NIST Inventors
Joel Ullom and Vincent Kotsubo
A compact, low power cryo-cooler for cryogenic systems capable of cooling gas to at least as low as 2.5 K. The cryo-cooler has a room temperature compressor followed by filtration. Within the cryostat, four counterflow heat exchangers precool the incoming high-pressure gas using the outflowing low
X-Ray Spectrometer

X-Ray Spectrometer

NIST Inventors
Kevin L. Silverman , Carl D. Reintsema , Galen O'Neil , Luis Miaja Avila , Daniel Swetz , W.Bertrand (Randy) Doriese , Dan Schmidt , Bradley Alpert , Joseph Fowler , Joel Ullom and Ralph Jimenez
This invention includes: an x-ray plasma source that produces primary x-rays; an x-ray optic that transmits and focuses the primary x-ray onto a sample jet from which fluorescence x-ray are emitted; and a microcalorimeter array detector that measures the energy of the incoming fluorescence x-rays
Created October 9, 2019, Updated October 23, 2023
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